大多数二尖瓣脱垂患者的预后与年龄、性别配对的对照组一样，都很好。[4]Nishimura RA, McGoon MD, Shub C, et al. Echocardiographically documented mitral valve prolapse: long-term follow-up of 237 patients. N Engl J Med. 1985 Nov 21;313(21):1305-9.http://www.ncbi.nlm.nih.gov/pubmed/4058522?tool=bestpractice.com 少数患者会出现严重的并发症，包括感染性心内膜炎、重度二尖瓣反流及心脏性猝死。
高风险患者可通过临床或超声心动图征象被确认，并需要较为警觉的随访。[23]Griffin BP. Timing of surgical intervention in chronic mitral regurgitation: is vigilance enough? Circulation. 2006 May 9;113(18):2169-72.http://circ.ahajournals.org/cgi/content/full/113/18/2169http://www.ncbi.nlm.nih.gov/pubmed/16684872?tool=bestpractice.com 促使重度二尖瓣反流风险增加的因素包括：男性、[33]Olson LJ, Subramanian R, Ackermann DM, et al. Surgical pathology of the mitral valve: a study of 712 cases spanning 21 years. Mayo Clin Proc. 1987 Jan;62(1):22-34.http://www.ncbi.nlm.nih.gov/pubmed/3796056?tool=bestpractice.com 年龄超过 45 岁、[34]Wilcken DE, Hickey AJ. Lifetime risk for patients with mitral valve prolapse of developing severe valve regurgitation requiring surgery. Circulation. 1988 Jul;78(1):10-4.http://www.ncbi.nlm.nih.gov/pubmed/3383395?tool=bestpractice.com 体质指数升高、高血压、[35]Hayek, E, Gring GN, Griffin BP. Mitral valve prolapse. Lancet. 2005 Feb 5-11;365(9458):507-18.http://www.ncbi.nlm.nih.gov/pubmed/15705461?tool=bestpractice.com 左心室增大、左心室功能不全，以及二尖瓣瓣叶增厚。[3]Marks AR, Choong CY, Sanfilippo AJ, et al. Identification of high-risk and low-risk subgroups of patients with mitral-valve prolapse. N Engl J Med. 1989 Apr 20;320(16):1031-6.http://www.ncbi.nlm.nih.gov/pubmed/2927482?tool=bestpractice.com[4]Nishimura RA, McGoon MD, Shub C, et al. Echocardiographically documented mitral valve prolapse: long-term follow-up of 237 patients. N Engl J Med. 1985 Nov 21;313(21):1305-9.http://www.ncbi.nlm.nih.gov/pubmed/4058522?tool=bestpractice.com
